Keen 5: The Armageddon Machine is the second episode in the Goodbye, Galaxy! series. In this episode, Keen confronts the Shikadi and attempts to destroy the Omegamatic, a device the Shikadi are building to destroy the galaxy.

These weapons are frequently found installed in roofs, floors and walls, and they shoot a single purple bullet approximately every three seconds. It is not known whether or not they are related to those found later in Fribbulus Xax.